DiskWarrior: "not enough contiguous space"? -What does this mean??

Question

Having issues, cannot reboot, after software update. Grey screen + Apple comes up, but no wheel and no further booting.
I'm able to boot from the DW CD.
Hard drive capacity is 74.41GB/ available space 21.81GB.
Graph of hard drive shows 5% out of order.
I rebuilt the directory which shows NO changes to the number or contents of files and folders... BUT...
"There is not enough contiguous free space for a fail-safe replacement of the directory. It is highly recommended that you create 132 MB of contiguous free space before replacing the original directory."
So what does this mean? Contiguous free space on the hard drive or in RAM?
(The hd doesn't seem to make sense, since it shows over 21GB of available space.)
I've ordered a new 1GB RAM module which should arrive Friday, but should I install this when the computer won't even boot on its own?
Help! I'm stuck and don't know what to do next. I have no idea how to go about creating 132 MB of contiguous free space.

Answer 1

DW is telling you it needs 132MB of contiguous — i.e., unfragmented — hard drive space. Apparently you don't have it, because all your free hard drive space is fragmented into segments smaller than 132MB. With nearly 21GB of free space in all, that's very surprising. It suggests that the files using space on your drive must be much more fragmented than is common in OS X, which defragments most files automatically without any input from you.
Ideally, what you would do to defragment everything on your drive, including the free space, is clone that drive to an external hard drive, and then clone the external drive back onto the internal drive. The second step in that process would erase the internal drive and then write everything back to it in unfragmented form.
But to do that, you'd have to be able to start the Powerbook up from a source disk that contained a cloning utility and enabled you to use it. The simplest way of doing that would be to have an external drive divided into two partitions: one small partition with an OS and a cloning utility (and perhaps other disk utilities) installed on it, so you could start up from it, and another larger partition of a suitable size for cloning the internal drive to: i.e., about the same size as the internal drive, or at a minimum, 10% larger than the amount of space that's actually used on the internal drive. If you don't already have such an arrangement, you're in no position to create one now except by going out and buying an external Firewire hard drive.